Historically Active Volcanoes of Alaska

This interactive map displays the location of the historically active volcanoes of Alaska. The 52 volcanoes listed meet at least one of the following criteria since 1700 CE: (1) documented, unquestioned eruption, or (2) a strongly suspected eruption, often an eruption documented in the historical account with very little information (current geologic knowledge must not contradict the eruption account), or (3) persistent (usually on the order of decades, but certainly longer than several months) fumaroles, with temperatures (where measured) within ~10°C of the boiling point, or (4) significant, measured, volcanic-related, non-eruptive deformation, (5) documented earthquake swarm with strongly suspected volcanic cause. For the purposes of this dataset a major eruptive event is considered to be one in which juvenile lava erupt as a lava flow or dome or as an explosive column reaching an altitude of several thousand meters above the vent.